BUG/MINOR: protocol: add missing support of dgram unix socket.
The proto "uxdg" (UNIX DGRAM) was not declared, causing an error trying
to put a socket unix on "dgram-bind" into a log-forward section.
This patch introduces the missing "uxdg" protocol by adding proto_uxdg.c
which was fully created based on the code available for the other
protocols.
This patch should be backported to version 2.3 and above.
diff --git a/src/proto_uxdg.c b/src/proto_uxdg.c
new file mode 100644
index 0000000..7eb5a62
--- /dev/null
+++ b/src/proto_uxdg.c
@@ -0,0 +1,151 @@
+/*
+ * DGRAM protocol layer on top of AF_UNIX
+ *
+ * Copyright 2020 HAProxy Technologies, Emeric Brun <ebrun@haproxy.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ */
+
+#include <ctype.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+
+#include <sys/param.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <sys/un.h>
+
+#include <haproxy/fd.h>
+#include <haproxy/listener.h>
+#include <haproxy/log.h>
+#include <haproxy/namespace.h>
+#include <haproxy/protocol.h>
+#include <haproxy/sock.h>
+#include <haproxy/sock_unix.h>
+
+static int uxdg_bind_listener(struct listener *listener, char *errmsg, int errlen);
+static void uxdg_enable_listener(struct listener *listener);
+static void uxdg_disable_listener(struct listener *listener);
+static int uxdg_suspend_receiver(struct receiver *rx);
+
+/* Note: must not be declared <const> as its list will be overwritten */
+struct protocol proto_uxdg = {
+ .name = "uxdg",
+
+ /* connection layer */
+ .ctrl_type = SOCK_DGRAM,
+ .listen = uxdg_bind_listener,
+ .enable = uxdg_enable_listener,
+ .disable = uxdg_disable_listener,
+ .add = default_add_listener,
+ .unbind = default_unbind_listener,
+ .suspend = default_suspend_listener,
+ .resume = default_resume_listener,
+
+ /* binding layer */
+ .rx_suspend = uxdg_suspend_receiver,
+
+ /* address family */
+ .fam = &proto_fam_unix,
+
+ /* socket layer */
+ .sock_type = SOCK_DGRAM,
+ .sock_prot = 0,
+ .rx_enable = sock_enable,
+ .rx_disable = sock_disable,
+ .rx_unbind = sock_unbind,
+ .receivers = LIST_HEAD_INIT(proto_uxdg.receivers),
+ .nb_receivers = 0,
+};
+
+INITCALL1(STG_REGISTER, protocol_register, &proto_uxdg);
+
+/* This function tries to bind dgram unix socket listener. It may return a warning or
+ * an error message in <errmsg> if the message is at most <errlen> bytes long
+ * (including '\0'). Note that <errmsg> may be NULL if <errlen> is also zero.
+ * The return value is composed from ERR_ABORT, ERR_WARN,
+ * ERR_ALERT, ERR_RETRYABLE and ERR_FATAL. ERR_NONE indicates that everything
+ * was alright and that no message was returned. ERR_RETRYABLE means that an
+ * error occurred but that it may vanish after a retry (eg: port in use), and
+ * ERR_FATAL indicates a non-fixable error. ERR_WARN and ERR_ALERT do not alter
+ * the meaning of the error, but just indicate that a message is present which
+ * should be displayed with the respective level. Last, ERR_ABORT indicates
+ * that it's pointless to try to start other listeners. No error message is
+ * returned if errlen is NULL.
+ */
+int uxdg_bind_listener(struct listener *listener, char *errmsg, int errlen)
+{
+ int err = ERR_NONE;
+ char *msg = NULL;
+
+ /* ensure we never return garbage */
+ if (errlen)
+ *errmsg = 0;
+
+ if (listener->state != LI_ASSIGNED)
+ return ERR_NONE; /* already bound */
+
+ if (!(listener->rx.flags & RX_F_BOUND)) {
+ msg = "receiving socket not bound";
+ goto uxdg_return;
+ }
+
+ listener_set_state(listener, LI_LISTEN);
+
+ uxdg_return:
+ if (msg && errlen) {
+ const char *path = ((struct sockaddr_un *)&listener->rx.addr)->sun_path;
+ snprintf(errmsg, errlen, "%s [%s]", msg, path);
+ }
+ return err;
+}
+
+/* Enable receipt of incoming connections for listener <l>. The receiver must
+ * still be valid.
+ */
+static void uxdg_enable_listener(struct listener *l)
+{
+ fd_want_recv_safe(l->rx.fd);
+}
+
+/* Disable receipt of incoming connections for listener <l>. The receiver must
+ * still be valid.
+ */
+static void uxdg_disable_listener(struct listener *l)
+{
+ fd_stop_recv(l->rx.fd);
+}
+
+/* Suspend a receiver. Returns < 0 in case of failure, 0 if the receiver
+ * was totally stopped, or > 0 if correctly suspended. Nothing is done for
+ * plain unix sockets since currently it's the new process which handles
+ * the renaming. Abstract sockets are completely unbound and closed so
+ * there's no need to stop the poller.
+ */
+static int uxdg_suspend_receiver(struct receiver *rx)
+{
+ struct listener *l = LIST_ELEM(rx, struct listener *, rx);
+
+ if (((struct sockaddr_un *)&rx->addr)->sun_path[0])
+ return 1;
+
+ /* Listener's lock already held. Call lockless version of
+ * unbind_listener. */
+ do_unbind_listener(l);
+ return 0;
+}
+
+/*
+ * Local variables:
+ * c-indent-level: 8
+ * c-basic-offset: 8
+ * End:
+ */